Determining future stroke risk using MRI

While the relative utility of MRI vs CT in the hyperacute management of acute brain ischemia remains controversial, there is little doubt that MRI remains the most useful imaging modality for the diagnostic evaluation of these patients. Aside from its superior sensitivity, higher resolution, and broad availability, MRI also detects abnormalities in many patients with transient ischemic neurologic symptoms.^1,2 Up to 50% of patients with TIA have diffusion-weighted imaging (DWI)–identified lesions on MRI if imaged within a few days of symptoms. Clinical features such as focal weakness and aphasia are associated with a higher probability of DWI positivity.³ MR angiography can also simultaneously detect abnormalities of the large extra- and intracranial arteries, an important cause of stroke.

A major clinical issue is identifying who is at high risk for early recurrent symptoms. Few data on high-risk neuroimaging characteristics are available. MRI and in particular DWI may be especially useful in this regard. Recent studies have reported specific MRI findings associated with an increased risk of early recurrence in these patients.^1,4,5 In one study, minor stroke and TIA patients with a lesion on DWI and a …